1. Field of the Invention
This invention relates to an optical information recording apparatus and an optical information recording method, which are applied to recording apparatus for, for example, compact discs (CD) and digital video discs (DVD).
According to the present invention, excellent pits are formed over the entire surface of a disc and a high quality disc in comparison with conventional discs is provided by controlling the timing of laser beam irradiation during recording correspondingly to the radial position where recording is now performed and the recording pattern.
2. Description of Related Art
Heretofore, for example, in a recording apparatus for compact discs namely an optical information recording medium of this sort, data for recording is subjected to data processing, followed by EFM (Eight-to-Fourteen Modulation), thus a bit string having a period of 3T to 11T is generated with respect to a predetermined basic period T, and an audio data is recorded.
Correspondingly, in a compact disc player, a laser beam is irradiated onto a compact disc and the return beam is received, a reproduction signal having the signal level which changes correspondingly to the light quantity of return beam is obtained, the reproduction signal is binarized with a predetermined slice level to generate a binarized signal. A PLL circuit is driven using the binarized signal to generate a reproduction clock, the binarized signal is latched successively by the reproduction clock, and a reproduction data having a period of 3T to 11T corresponding to the pit string formed on a compact disc is generated.
The compact disc player decodes the reproduction data generated as described herein above by performing data processing corresponding to the data processing performed when recording, and the audio data recorded in a compact disc is reproduced.
As for recording and reproduction of such conventional compact disc (CD), Japanese Published Unexamined Patent Application No. Sho 58-2628 discloses a disc recording apparatus in which the pit is formed on a disc so that a reproduction signal is obtained without deviation from the recording signal by changing output power of a laser beam and by reducing the pulse width of a pulse signal. Japanese Published Unexamined Patent Application No. Hei 3-83230 discloses an optical recording apparatus in which a write pulse having a pulse width shorter by pulse width decrement corresponding to the length increment of the pit due to a thermal time constant of the optical recording medium is generated from a base band signal, the recording light which is pulse width-modulated using the write pulse is irradiated onto the optical recording medium, and the pit with a normal length is formed on the optical recording medium having a large thermal time constant correspondingly to the base band signal. Japanese Published Unexamined Patent Application No. Sho 62-54830 discloses an optical disc recording reproduction apparatus for realizing the optimal recording condition of a used disc and environmental condition regardless of difference in recording sensitivity of respective discs or regardless of fluctuation of a laser beam due to temperature change to improve the reliability of the reproduction signal, and for realizing high density information recording in which apparatus recording is performed with successive changing of the pulse width of the laser beam and the pulse width is selected when the pulse width of the reproduction signal is in a predetermined desired range.
Recently, reproduction of a compact disc at high transmission rate has been generalized. In a high transmission rate reproduction apparatus, a compact disc is rotated, for example, at a speed 8 or more times the prescribed speed to reproduce data at high rate. By using a high transmission rate reproduction apparatus, data of the same quantity is obtained within a far shorter time in comparison with the conventional transmission rate.
In order to reproduce data at a high transmission rate, high speed disc rotation and wide band electronic circuits are required. Because a wide band electronic circuit is generally involved in high noise level problem, in order to reproduce signals stably in high noise level environment, jitter of a disc should be reduced.
The present invention has been accomplished in view of this point, it is the object of the present invention to provide an optical information recording apparatus and an optical information recording method which are capable of reducing jitter generated from a disc and capable of decoding signals stably at high transmission rate.